Organic Light-Emitting Diode (OLED) displays have become a hot field for flat panel display research. Compared with a Liquid Crystal Display (LCD), an OLED display has advantages in lower power consumption, a lower production cost, a wider viewing angle, a faster response speed and is self-luminous. Among presently existing technologies, OLED displays have come to take the place of traditional LCDs in flat panel displays such as mobile phones, Personal Digital Assistants (PDAs) and digital cameras. Pixel circuit design is a core content of OLED display technology and has great research significance.